1. Field of the Invention
The present invention relates to ceramic powder that forms a fine ceramic product which is used to produce an artificial tooth at a dental laboratory and also relates to a method of producing an artificial tooth by settling a ceramic product.
2. Description of the Related Art
Ceramic powders are chiefly used to restore the crown of a tooth or to form an artificial tooth in dental clinics today. In one method, a ceramic powder is dissolved in water or a special mixture liquid mixed with an additive such as glycerin that slows drying for assuring an easy-to-handle feature to make a ceramic paste, which is thickened and shaped by a brush or other instruments. To match complex coloration of a tooth, ceramic powders of a plurality of colors are sequentially applied and are compacted and then hardened by adding vibration while an adjustment is gradually performed.
A high skill level is needed for a series of steps in which the ceramic powder is molded into the shape of a tooth while moisture is oozed out therefrom through vibration to compact and harden the ceramic material. Since the ceramic material needs to be free from deformation and maintain its form, ceramic powders in a wide range of particle size are mixed. When mixed, molding and vibration of the ceramic material and moisture oozing are insufficient in a mixture of ceramic powders in a wide range of particle size, particles in particular range are distributed in a localized region, leading to a localized defect after a firing process. If the localized distribution is left for a long period of time, mixture is different from position to position, and it is impossible to restore uniform distribution of the particles. Once mixed, the ceramic powders, even unused, have to be discarded at the moment drying starts.
The above-described conventional ceramic powder can be mixed in a mixing liquid such as water and then poured into a core. Since consideration is given to preventing a run of material in the course of molding in the conventional ceramic material, the pouring method does not work in the conventional ceramic powder. More specifically, when the ceramic powder is mixed in water, particles precipitate for a short period of time and are hardened inconsistently. Pouring the particles into a fine area is difficult. After pouring, the particles are distributed in a localized region, and uniformly compacting the particles through vibration is difficult. The ceramic material is thus subject to cracks and deformation in the course of drying. Especially when additional molding is performed, a crack is likely to take place during a firing process.